Environment Pollution – Water Pollutants
Sources – community waste water, Industrial waste, Agricultural chemicals waste, Thermal & nuclear pollution, Oil spills, Radioactive dump waste, Groundwater seepage etc.
- Sudden rise in water temperature due to thermal pollution, which uses water as coolant & releases hot water to source, kills aquatic animals as they have a very narrow tolerance limit with respect to temperature
- Polluted water reduces dissolved oxygen which leads to depletion of aquatic flora & fauna
- Oil spills in water can be cleaned with the help of Bregoli – a byproduct of paper industry
- Water hyacinth (an aquatic weed) can purify water by taking some toxic materials & a number of heavy metals from water.
Biochemical oxygen demand
- amount of dissolved oxygen needed by bacteria in decomposing the organic waste present in water
- Actually a measurement of pollution by organic wastes expressed as milligram of oxygen / liter water
Higher value of BOD indicates low dissolved oxygen in water (BOD is only limited to biodegradable materials only)
Chemical oxygen demand
- a measure of oxygen equivalent required for oxidation of total organic matter i.e. degradable & non degradable, present in water.
Diseases by Water Pollution
- A crippling deformity caused by methyl mercury poisoning mainly by industrial waste water
- first described in the inhabitants of Minamata Bay, Japan and resulted from their eating fish contaminated with mercury industrial waste
- Also known as ouch ouch disease (pain in bones & joints) caused by water contamination by cadmium
Blue Baby Syndrome
- Excess nitrates in drinking water reacts with hemoglobin to form nonfunctional methaemoglobin which impairs oxygen transport
- Excess of fluorides in drinking water can cause neuromuscular disorders, teeth deformity, and hardening of bones, painful joints & outward bending of legs from knees – Knock knee syndrome
Black foot disease
- Caused by leaching of arsenic from soil & rocks to ground water used for drinking purposes
Water contaminated with lead
- Cause anemia, loss of muscle power & bluish lines around the gums
- Produced by nuclear tests, passed to vegetation & then appears in milk of the cattle that consume the contaminated vegetation & is passed to humans.
- causes serious damage to thyroid glands especially among children
Sick building syndrome (SBS)
- a situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified
- causes are frequently pinned down to flaws in the heating, ventilation & air conditioning (HVAC) systems
Pollution in Leather Industry
- Leather industry in India has become 0 discharge industry as ~80% of the effluents are treated and recycled back into use and remaining 20% are solidified and their salts used for other purposes.
- As a result, Indian leather industry is REACH compliant (EU norms) and exported $4.5 bio in 2011-12 and the target is $14 bio by 2015-16 (growth rate of 20% p.a.)